Re: [Dart] [tsvwg] I-D Action: draft-ietf-tsvwg-rtcweb-qos-02.txt

["Black, David" <[e-mail]>]

Karen,

<WG chair hat off>, [+dart list]

> I wonder if the recommendations of this document should not relate to the
> viability (or rather the opposite) of
> handling different RTCWEB data channels individually from a DSCP markings
> perspective. Or more generally
> relate to the fact that media streams within the same congestion control
> context cannot be handled individually.
> Right now such considerations are not in the document. If the intention is
> for such consideration to come
> in documents from the dart wg, then it would be very important to  have a
> reference to this dependency - or ?

IMHO, such a reference is necessary, although the dart WG draft will be
informational.  The reference should be added once there is an official dart
WG draft (likely to happen this week).

> Something else:
>
> Right now the document stipulates that packets within the same media stream
> may be marked with different DSCP codepoints, i.e.,
> it is said:
> 
>    One may select difference drop precedences for the
>    different packets in the media flow.  Therefore, all packets in the
>    stream SHOULD be marked with the same priority but can have
>    difference drop precedences.
> 
> which indeed is in compliance with the recommendations put forward in
> draft-york-dart-dscp-rtp-00 in that
> it ensures that the DSCP markings  do not result in re-ordering  within the
> media flow, but has it been ascertained, from a CC
> perspective that usage of different drop precedence within the same CC
> context is viable ?

Good question - I will include that in my slides for the dart WG meeting.

> >From the RTCWEB data channel perspective this certainly isn't viable (being
> SCTP based),
> whether it is viable from an RMCAT CC perspective is something that we in
> the RMCAT wg would need to
> make more clear.

What's the rationale for "certainly isn't viable" regarding different drop
precedences within a single SCTP session?

Thanks,
--David (as an editor of draft-york, *not* as a tsvwg WG chair)

> -----Original Message-----
> From: tsvwg [mailto:[e-mail]] On Behalf Of Karen E. Egede
> Nielsen
> Sent: Sunday, July 20, 2014 4:49 PM
> To: [e-mail]
> Cc: rmcat WG
> Subject: Re: [tsvwg] I-D Action: draft-ietf-tsvwg-rtcweb-qos-02.txt
> 
> Hi,
> 
> Please accept the following comments:
> 
> I wonder if the recommendations of this document should not relate to the
> viability (or rather the opposite) of
> handling different RTCWEB data channels individually from a DSCP markings
> perspective. Or more generally
> relate to the fact that media streams within the same congestion control
> context cannot be handled individually.
> Right now such considerations are not in the document. If the intention is
> for such consideration to come
> in documents from the dart wg, then it would be very important to  have a
> reference to this dependency - or ?
> 
> Something else:
> 
> Right now the document stipulates that packets within the same media stream
> may be marked with different DSCP codepoints, i.e.,
> it is said:
> 
>    One may select difference drop precedences for the
>    different packets in the media flow.  Therefore, all packets in the
>    stream SHOULD be marked with the same priority but can have
>    difference drop precedences.
> 
> which indeed is in compliance with the recommendations put forward in
> draft-york-dart-dscp-rtp-00 in that
> it ensures that the DSCP markings  do not result in re-ordering  within the
> media flow, but has it been ascertained, from a CC
> perspective that usage of different drop precedence within the same CC
> context is viable ?
> 
> >From the RTCWEB data channel perspective this certainly isn't viable (being
> SCTP based),
> whether it is viable from an RMCAT CC perspective is something that we in
> the RMCAT wg would need to
> make more clear.
> 
> BR, Karen
> 
> > -----Original Message-----
> > From: tsvwg [mailto:[e-mail]] On Behalf Of internet-
> > [e-mail]
> > Sent: 23. juni 2014 21:12
> > To: [e-mail]
> > Cc: [e-mail]
> > Subject: [tsvwg] I-D Action: draft-ietf-tsvwg-rtcweb-qos-02.txt
> >
> >
> > A New Internet-Draft is available from the on-line Internet-Drafts
> > directories.
> >  This draft is a work item of the Transport Area Working Group Working
> > Group of the IETF.
> >
> >         Title           : DSCP and other packet markings for RTCWeb QoS
> >         Authors         : Subha Dhesikan
> >                           Cullen Jennings
> >                           Dan Druta
> >                           Paul Jones
> >                           James Polk
> > 	Filename        : draft-ietf-tsvwg-rtcweb-qos-02.txt
> > 	Pages           : 7
> > 	Date            : 2014-06-23
> >
> > Abstract:
> >    Many networks, such as service provider and enterprise networks, can
> >    provide per packet treatments based on Differentiated Services Code
> >    Points (DSCP) on a per-hop basis.  This document provides the
> >    recommended DSCP values for browsers to use for various classes of
> >    traffic.
> >
> >
> > The IETF datatracker status page for this draft is:
> > https://datatracker.ietf.org/doc/draft-ietf-tsvwg-rtcweb-qos/
> >
> > There's also a htmlized version available at:
> > http://tools.ietf.org/html/draft-ietf-tsvwg-rtcweb-qos-02
> >
> > A diff from the previous version is available at:
> > http://www.ietf.org/rfcdiff?url2=draft-ietf-tsvwg-rtcweb-qos-02
> >
> >
> > Please note that it may take a couple of minutes from the time of
> > submission
> > until the htmlized version and diff are available at tools.ietf.org.
> >
> > Internet-Drafts are also available by anonymous FTP at:
> > ftp://ftp.ietf.org/internet-drafts/